1. Field of the Invention
The present invention relates to an organic light-emitting display apparatus and a method of manufacturing the same. More particularly, the invention relates to an organic light-emitting display apparatus with reduced defect rates due to particles, and having a film encapsulation structure with improved resistance to moisture.
2. Description of the Related Art
An organic light-emitting device is a self-luminescent device that may be applied to various products, such as thin and flexible display apparatuses. However, device properties of such an organic light-emitting device drastically deteriorate when the device is exposed to moisture and oxygen from the external environment.
Therefore, after an organic light-emitting device is fabricated, the organic light-emitting device is encapsulated by using a can or a glass substrate, wherein a polymer material, such as UV ray-hardening epoxy, thermal hardening epoxy, or acryl, is generally used as sealant material. However, since a polymer material is weak against moisture, properties of an organic light-emitting device, such as brightness, deteriorate due to moisture and oxygen permeating into the organic light-emitting device over time, and thus the lifespan of the organic light-emitting device is reduced. To prevent the deterioration, a moisture absorbent member, which absorbs moisture, is installed in a display apparatus to prevent moisture transmitted through a sealant from affecting the organic light-emitting device. However, this technique makes the manufacturing process complicated overall, and increases the weight and volume of a fabricated display apparatus.
To resolve this problem, a film encapsulation method for encapsulating a display device by covering the display device with a protective film has been introduced. A film encapsulation material used in the film encapsulation method is a material directly related to the lifespan of a manufactured organic light-emitting device, and thus it is necessary to appropriately adjust conditions, including moisture permeability, adhesiveness with respect to a device material, and a thermal expansion coefficient. In particular, the moisture permeability is the most important factor which significantly affects the lifespan of an organic light-emitting device. Moisture permeation through a film encapsulation material includes vertical permeation with respect to a surface of a film and lateral permeation through a section of a display apparatus, that is, a non-luminescent area.
Although a conventional film encapsulation method effectively prevents permeation of moisture or oxygen in a direction perpendicular to a substrate, moisture and oxygen may permeate along interfaces of an encapsulation layer from ends of a film in a direction parallel to the substrate.